Identify a comic where Scrooge McDuck was protected against a beam because he went swimming in his money

Question

I remember reading a Donald Duck magazine or comic once (at least a decade ago, but the comic was already old by then) where Scrooge McDuck had built resistance against some kind of radiation or ray weapon because swimming in his money all his life added a protective layer of gold dust to his feathers. However, I cannot remember the type of radiation or weapon it was protecting against. I also cannot remember whether this was explained in the beginning of the comic (followed by a long string of attempts to get him to lose this gold dust by the villain of the week) or at the end of the comic as a way to explain a deus ex machina in the finale of the comic.

What was Scrooge McDuck protected against by his gold dust layer?

Answer 1

This is Uncle Scrooge #08, The Mysterious Stone Ray

The device was a petrification ray, developed to defend the island by a Professor from Duckburg trying to perfect a recipe for fumeless cabbages